Devices, systems, and methods for detecting substances

A microfluidic device for the detection of drugs, explosives, chemical warfare, or other substances which is able to directly accept a swab into the device for testing. This device additionally contains on-board reagents to perform colorimetric testing for threshold determination directly in the device. These features are useful in a wide array of situations, such as at security checkpoints, environmental monitoring, clinical analysis, which require testing completely unknown substances and therefore must test for multiple different substances in one test. This is especially useful for police and other law enforcement officials who often must use field-deployable platforms making accurate field-testing critical for safety.